|HIS Radeon HD6870 IceQ-X Turbo-X Video Card|
|Reviews - Featured Reviews: Video Cards|
|Written by Steven Iglesias-Hearst|
|Thursday, 02 June 2011|
Page 17 of 18
HIS HD6870 IceQ X Turbo X Overclocking
Before I start overclocking I like to get a little bit of information, firstly I like to establish operating temperatures and since we know the IceQ X cooler is quite capable we can quickly move forward. Next I like to know what the voltage and clock limits are, so I fired up the MSI's Afterburner utility. I established that vCore was adjustable between 800mV and 1.299V and clock speeds were limited to 1200MHz max on the GPU and 1250MHz (5GHz effective) maximum frequency for the memory. This is more than enough range to move forward with and I know I can squeeze every last drop of performance out of the HIS HD6870 IceQ X Turbo X. My preferred weapons are MSI Afterburner (v2.2.0 Beta 3) for fine tuning while using FurMark (v1.9.0) to heat the GPU.
The GPU-Z screenshot above serves as a reminder of the temperatures and speed the HIS HD6870 IceQ X Turbo X video card at its default settings. With my modified fan profile running I gradually bumped the vCore to max and was able to push the clock speeds to 1020MHz GPU and 1220MHz (4.88GHz effective) Memory and still remain stable while in FurMark.
With a 45MHz GPU overclock (120MHz over reference design) and a 70MHz memory overclock (170MHz over reference design) we went back to the bench and ran through the entire test suite. Overall there is an average 4.75% increase in scores (at 1920x1080 resolution). We also re ran temperature tests at the overclocked speeds with a slightly higher ambient temperature of 25°C. The IceQ X cooler on the HIS HD6870 Turbo X (with modified fan profile) once again pulled through and gave some good temperatures. At idle the GPU sat at 42°C (47% fan speed). Pushing the temperature up with FurMark saw the GPU load temperature rise to 72°C (73% fan speed) and cranking the fan on manual to 100% saw the temperature drop to 66°C.
The two problem benchmarks (Vantage: New Calico and Unigine Heaven) required the fan to be running at 100% in order for the test to complete successfully under the overclocked settings, this means a more aggressive fan profile is needed to run this video card with a long term overclock, either that or just keep the fan running at 100%.
That's all of the testing over, in the next section I will deliver my final thoughts and conclusion.